Dual station interlocking parking brake

ABSTRACT

A brake control for a vehicle with a source of fluid pressure having a pair of actuator valves for directing fluid pressure from the source to the brake to effect its release and a selector valve for selectively directing fluid pressure from the source to one of said actuator means while isolating the other actuator means from said source.

United States Patent DUAL STATION INTERLOCKING PARKING BRAKE 7 Claims, 1Drawing Fig.

References Cited UNITED STATES PATENTS 8/1934 Wolfe et al. 303/13X5/1936 Vorech et 303/13 4/1941 Stanley 303/13 8/1942 Davis 303/13Primary Examiner-Milton Buchler Assistant Examiner-John J. McLaughlinAttorney-Noel G. Artman U.S. Cl 303/ 13,

180/77, 188/ 106, 303/2 ABSTRACT: A brake control for a vehicle with asource of Int. Cl B60t 13/38, fluid pressure having a pair of actuatorvalves for directing B60t 17/ 1 8 fluid pressure from the source to thebrake to effect its release Field of Search /77, 77 and a selector valvefor selectively directing fluid pressure (S); 188/106, 106 (P); 303/13,9, 2, 14, 68-69, 6, from the source to one of said actuator means whileisolating 6 (A) the other actuator means from said source.

62 /j2 64 Q l i T XI HAN as Q1 FPON? T 574770 46' 48 I nun T) l w l DUALSTATION INTERLUCKING PARKING BRAKE BACKGROUND AND SUMMARY OF THEINVENTION In certain large vehicles, such as those utilized to tow thejumbo jet aircraft, the size of the machine requires a control oroperatorss compartment at each end. Manipulation of such a large vehiclein close proximity to the aircraft, which is necessary to effect thephysical connection between the tow tractor and the aircraft itself, andoften also to provide ground support for the electrical andair-conditioning systems within the aircraft, requires that the operatorbe located in a position to readily observe and judge the distance tothe various aircraft appendages. Any damage to the aircraft must beprecluded and to achieve this goal no contact with the aircraft can betolerated. Dual operator stations, one at either end of the vehicle, areprovided so that the operator may be positioned at the forward end ofthe vehicle regardless of its direction of travel. Dual operatorstations, however, require the operator to physically leave one stationand walk to the other. During this span of time, the vehicle wouldnormally be unattended and a parking brake must be provided to preventthe vehicle from rolling. It is therefore apparent that the brake mustbe capable of being applied from one station and released at the other.

it is therefore an object of the present invention to provide a controlmeans for a parking brake which permits the applicationof the brake inone location on the vehicle and the release of the brake from adifferent location.

It is also an object of the present invention to provide a control meansfor a parking brake which will physically indicate by movement of themanual brake actuator means at one location that the brake has beenapplied at the other location.

Another object of the invention is to prevent inadvertent release of theparking brake, once it has been applied, through movement of the stationselector valve.

These, and other objects of the present invention and many of itsattendant advantages will become apparent upon a perusal of thefollowing description of a preferred embodiment made with reference tothe drawing of which the FIG. is a schematic view of a braking systemembodying the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT A vehicle, which may be of thetype disclosed in application Ser. No. 796,37l filed Feb. 4, 1969, isprovided with a from station, schematically indicated at 10, and a rearstation, schematically indicated at 12. The parking brake 14 isprovided'on the vehicle to retard or stop a shaft 16 comprising aportion of the drive train for the vehicle. The parking brake 14includes a piston member 18 which is reciprocally mounted within acylinder Zll. An extension 22 formed on the piston 18 protrudes from thecylinder 20 and is frictionally engageable with a disc member 24 securedto the shaft 16. A spring member 26 positioned between the piston 18 andthe end wall of the cylinder 20 urges the extension member 22 intofrictional engagement with the disc 24. A conduit 28 communicates withthe interior of the cylinder 20 at the end of the cylinder oppositethespring member 26. Providing fluid under pressure through the conduit 28will urge the piston member 1% to the right as viewed in the drawingagainst the bias of the spring 26, thereby disengaging or releasing theparking brake.

The fluid utilized is preferably air and is provided from a reservoir30. A conduit 32 connects the reservoir with the selector valve 34. Thestation selector valve is a two-position type, the front position ofwhich will connect the conduit'32 with the conduit 36 while connectingconduit 38 with the exhaust conduit 40 and the rear position connectsthe conduits 32 and 36 with conduits 38 and 40 respectively. The conduit36 is connected to the front brake actuator valve 42 and the conduit 38is connected with the rear brake actuator valve 44, while the conduit 40is open to atmosphere.

The front actuator valve 42 is a two-position type which is movableeither through the manual control means 46 between an applied positionand a release position and is also movable to its applied position by anair actuator 48. In the release position, as shown in the drawing, theconduit 36 is placed in fluid communication with the conduit 50, whichconduit is connected with the conduit 28 leading to the cylinder 20through a tee connector 52. Two other conduits 54 and 56 are incommunication with the front actuator valve 42. In the release positionthe conduit 54 is placed in communication with the conduit 56 which isvented to atmosphere. Conduit 54 is connected at its other end with anair actuator valve 58 associated with and controlling the position ofthe rear actuator valve 44. Movement of the front actuator valve to itsapply position connects the pressure conduit 36 with conduit 54, whichcauses the air actuator mechanism 58 to move the rear actuator valve 44to its apply position, and connects the conduit 50 with the conduit 56,which will exhaust fluid pressure from the cylinder 20 through conduits28, connector 52 and conduits 50 and 56. The rear actuator valve 44 alsohas a manual actuator means 60 which manually controls the posi' tion ofthe rear actuator valve 44 in addition to the air actuator means 58which is capable of moving the rear actuator valve 44 to its applyposition. ln addition to conduit 38, three other conduits are incommunication with the rear actuator valve 44, namely conduit 62, 64 and66. Conduit 62 is connected at its other end with the tee connector 52,the conduit 64 communicates with the air actuator means 48 on the frontactuator valve 42 while the conduit 66 is an exhaust conduit open to theatmosphere, ln its release position, the conduit 36 is in communicationwith conduit 62 and permits the communication of air pressure to thecylinder 20 to the conduits 38 and 62 through tee connector 52 andconduit 28. Simultaneously, the air actuator 48 is exhausted throughconduit 64 and 66. in the apply position, the pressure conduit 38 isplaced in communication with the conduit 64 which permits the airpressure to act upon the air actuator means 48 to also shift the frontactuator valve 42 to its apply position. Simultaneously the conduit 62leading from the tee connector 52 is exhausted to atmosphere through theconduit 66.

The tee connector 52 includes a shuttle valve which is represented by apair of seats 68 and 70 and a ball check 72. The ball 72 is forcedagainst the seat 68 to seal off the conduit 62 whenever air underpressure is present in the conduit 50. Similarly the ball 72 will beforced against the seat 70 to seal off the conduit 50 whenever air underpressure is present in the conduit 62. The ball 72 is movable betweenthese two positions to maintain the brake in its released positionregardless of the position of the selector valve 34.

it will be apparent from the foregoing description of of a preferredembodiment, that the present invention provides a control means for aparking brake which is operable from either end of the vehicle, whichprovides a visual indication that the brake has been applied whenevereither the front actuator valve or the rear actuator valve have beenmoved to the apply position and which, by shifting the nonselectedstation actuator valve to its apply position, once the selected stationvalve has been moved to its apply position, the parking brake cannot bereleased simply by moving the selector valve.

it is to be understood that various changes and modifications may bemade, such as, for example, substitution of an air over hydraulic systemfor the straight air system disclosed to actuate the parking brake,without departing from the scope of the invention.

lclaim:

T. ln a vehicle having dual control stations, a brake which isoperatively connected to prevent movement of the vehicle when applied,and a source of fluid under pressure, the improvement comprising:

first and second actuator valves, one of which is located in eachstation, each actuator valve having a release position in which saidfluid pressure is directed to release said brake and an apply positionin which fluid pressure is exhausted to apply said brake; and

a selector valve for selectively connecting the source of fluid pressureto one of said actuator valves while simultaneously isolating the otherof said actuator valves from said source.

2. ln a vehicle according to claim 1, and further comprising:

first and second pilot-operated actuator means operatively connected tothe first and second actuator valves respectively for moving theassociated actuator valve to its apply position in response to receivinga pressure signal; and

conduit means extending between the first actuator means and the secondactuator valve and between the second actuator means and the firstactuator valve, each of said actuator valves being capable of directinga fluid pressure signal through said conduit means when moved to itsapply position.

3. in a vehicle according to claim 2 wherein said actuator valves aremovable from their release positions only by said actuator means and bythe application of manual force.

4. In a vehicle according to claim 1, and further comprising shuttlevalve means interposed between said actuator valves and said brake forpermitting communication between the brake actuator valve to which fluidpressure is directed by said selector valve while isolating the other ofsaid actuator valves from the brake.

5. A means for controlling the parking brake from either one of twooperator stations on a vehicle having a source of fluid pressure, saidcontrol means comprising:

a pair of actuator valves one of which is located in each station, eachactuator valve having a release position and an apply position; and

a selector valve for selectively connecting said source to one of saidactuator valves while simultaneously isolating the other of saidactuator valves from said source.

6. The invention according to claim 5, and further comprisapilot-operated actuator means operatively connected to each of saidactuator valves for moving the associated actuator valve to its applyposition in response to receiving a pressure signal;

conduit means extending between each actuator valve and the actuatormeans associated with the other actuator valve; and

each of said actuator valves being capable of directing a pressuresignal through said conduit means when moved to its apply position.

7. The invention according to claim 6, and further comprising checkvalve means interposed between the actuator valves and the parking brakefor permitting communication between the actuator valve to which fluidpressure is directed by the selector valve while isolating the otheractuator valve from the parking brake.

1. In a vehicle having dual control stations, a brake which isoperatively connected to prevent movement of the vehicle when applied,and a source of fluid under pressure, the improvement comprising: firstand second actuator valves, one of which is located in each station,each actuator valve having a release position in which said fluidpressure is directed to release said brake and an apply position inwhich fluid pressure is exhausted to apply said brake; and a selectorvalve for selectively connecting the source of fluid pressure to one ofsaid actuator valves while simultaneously isolating the other of saidactuator valves from said source.
 2. In a vehicle according to claim 1,and further comprising: first and second pilot-operated actuator meansoperatively connected to the first and second actuator valvesrespectively for moving the associated actuator valve to its applyposition in response to receiving a pressure signal; and conduit meansextending between the first actuator means and the second actuator valveand between the second actuator means and the first actuator valve, eachof said actuator valves being capable of directing a fluid pressuresignal through said conduit means when moved to its apply position. 3.In a vehicle according to claim 2 wherein said actuator valves aremovable from their release positions only by said actuator means and bythe application of manual force.
 4. In a vehicle according to claim 1,and further comprising shuttle valve means interposed between saidactuator valves and said brake for permitting communication between thebrake actuator valve to which fluid pressure is directed by saidselector valve while isolating the other of said actuator valves fromthe brake.
 5. A means for controlling the parking brake from either oneof two operator stations on a vehicle having a source of fluid pressure,said control means comprising: a pair of actuator valves one of which islocated in each station, each actuator valve having a release positionand an apply position; and a selector valve for selectively connectingsaid source to one of said actuator valves while simultaneouslyisolating the other of said actuator valves from said source.
 6. Theinvention according to claim 5, and further comprising: a pilot-operatedactuator means operatively connected to each of said actuator valves formoving the associated actuator valve to its apply position in responseto receiving a pressure signal; conduit means extending between eachactuator valve and the actuator means associated with the other actuatorvalve; and each of said actuator valves being capable of directing apressure signal through said conduit means when moved to its applyposition.
 7. The invention according to claim 6, and further comprisingcheck valve means interposed between the actuator valves and the parkingbrake for permitting communication between the actuator valve to whichfluid pressure is directed by the selector valve while isolating theother actuator valve from the parking brake.